Executive Summary
A large government department operating in a regulated, security-sensitive environment holds one of the UK’s largest datasets related to citizen identity. As part of its modernisation agenda, the client aimed to exit legacy technology platforms, improve agility, and become a data-centric organisation. With data underpinning critical public-facing services, there was a need to shift from fragmented, supplier-managed infrastructure to secure, cloud-ready, modular architectures.
However, the client lacked a formal data architecture capability. Data was siloed, governance was inconsistent, and there was no coherent metadata or information management strategy. A&A Digital Tech was engaged to architect a modern, secure, and standards-aligned data architecture function to enable the client’s digital transformation and deliver a scalable, maintainable future state for data operations.
The Challenge
The legacy data landscape was characterised by vendor lock-in, absence of reusable data models, and manual data flows that limited insight and operational efficiency. There was no established Target Data Architecture or architectural principles to guide migration away from monolithic systems.
Additionally:
🗄️ Data Volume & Sensitivity
Over 800 million sensitive records required migration under strict OFFICIAL-SENSITIVE classification controls, posing significant regulatory and assurance challenges.
📉 Lack of Governance & Standards
There were no enterprise-wide data models, lineage definitions, or stewardship practices. Metadata was inconsistent or absent, undermining operational visibility and insight generation.
💡 Low Cloud Readiness
Internal teams had limited experience with modern cloud-native architectures. Security and compliance stakeholders were unfamiliar with zero-trust and serverless concepts.
🏗️ Outdated Delivery Methods
The operating environment remained heavily waterfall-driven, slowing agility, hampering iterative design, and creating silos between architecture, delivery, and assurance teams.
⚠️ Siloed Security Architecture
Security and compliance controls were applied reactively, often duplicating effort across teams and introducing risk into transformation programmes.
Our Approach and Solution
A&A Digital Tech established a greenfield data architecture function for the client, aligning with modern enterprise architecture principles and UK Government DDaT standards. The solution combined architectural leadership, practical implementation support, and organisational change enablement.
1. Establishing Core Data Architecture Foundations
🧱 Defined a formal Target Data Architecture aligned to business domains using Domain-Driven Design (DDD)
📚 Developed governance frameworks, metadata standards, and data quality principles
🧭 Created architecture decision records (ADRs) and reusable reference models
2. Data Transition Strategy
📦 Designed a secure, phased strategy to migrate 800M+ records
🛡️ Embedded data-centric security patterns with OFFICIAL-SENSITIVE compliance
📋 Established validation and rollback controls across transitions
3. Cloud-Native Data Enablement
☁️ Designed hybrid cloud architecture using Azure Stack and AWS-native services
🔗 Introduced GraphQL APIs and event-driven streaming models
🧩 Enabled platform-independent integration contracts across services
4. Embedded Architecture Governance
📊 Established federated governance with TDA, domain, and platform architects
📑 Delivered artefacts: data lineage models, domain blueprints, metadata catalogues
🧵 Aligned cross-functional teams to agile architecture practices
5. Capability Transfer and Uplift
🎓 Delivered structured training on cloud-native data architecture patterns
🤝 Embedded A&A Digital Tech architects into squads for mentoring and collaborative delivery
🧠 Built internal ownership and long-term architectural maturity
Outcomes
🏛️ Established a Data Architecture Practice – Created an enterprise-wide data capability aligned to digital strategy
📦 Executed a Strategic Data Migration – Successfully transitioned 800M+ classified records securely
✅ Achieved Government Security Approvals – Platform cleared by national assurance bodies
☁️ Delivered a Secure Serverless Platform – Designed for OFFICIAL-SENSITIVE hosting and resilience
💸 Reduced Operational Costs – Enabled legacy exit and modern hosting efficiency
🔄 Enabled Digital Agility – Through reusable GraphQL APIs and event-based data access
🧾 Institutionalised Metadata Standards – Embedded catalogue, lineage, and governance controls
🤝 Improved Cross-Team Collaboration – Through embedded architecture leadership
Key Learnings & Takeaways
📐 Start with Architecture – Establishing a clear data strategy early prevents rework and fragmentation
👥 Embed to Align – Architecture embedded in delivery teams accelerates decision-making
🔐 Design for Security – Zero-trust and data-centric models enable faster approvals
🚀 Modern Patterns Matter – Serverless, hybrid cloud, and GraphQL drive scale and savings
📖 Documentation is Key – Decision logs and artefacts increase reuse and auditability
⚖️ Flex for Context – Hybrid delivery models work best in government transformation
📊 Governance Drives Adoption – Clear roles and policies lead to long-term sustainability
